The movable wall portion attachment mechanism of an incubator, which has the above arrangement, has been conventionally known as disclosed in EP 0 811 363 A2 (to be referred to as “patent literature 1” hereinafter). The movable wall portion attachment mechanism (to be referred to as “the movable wall portion attachment mechanism in patent literature 1” hereinafter) of the incubator disclosed in patent literature 1 allows a doctor, a nurse or the like to provide various kinds of treatments for an infant, e.g., a newborn infant, lying on the bed base provided in the infant accommodation space of the incubator. That is, an operator such as a doctor, a nurse or the like makes at least one movable wall portion in a substantially erect position (in other words, in a closed state) pivot forward to the outside about a portion of a region including the lower end portion and its vicinity to set it in a substantially hanging position. This opens at least one side surface of the infant accommodation space, and hence allows a doctor, a nurse or the like to approach the infant from the open side surface and easily and quickly provide a necessary treatment for the infant. After providing a treatment, the doctor, the nurse or the like can close the infant accommodation space by making the movable wall portion in a substantially hanging position pivot backward in the direction opposite to that of the above forward pivoting movement.
With the movable wall portion attachment mechanism in patent literature 1, however, when the operator roughly shuts the movable wall portion, the movable wall portion impulsively comes into contact with the incubator base side or the like. This generates large sound and large vibration or damages part of the incubator base or part of a wall portion such as the movable wall portion or the like forming the infant accommodation space.